Table 1.
Selected characteristics among 2,535 older adults aged ≥60 and stratified by social isolation and sex: NHANES 1999–2002 a
| Characteristics | Overall (N = 2,535) | Men (n = 1,267) | Women (n = 1,268) | ||||
|---|---|---|---|---|---|---|---|
|
|
|||||||
| Socially isolated (n = 190) | Not isolated (n = 1,077) | P - Value | Socially isolated (n = 270) | Not isolated (n = 998) | P - Value | ||
|
|
|||||||
| Age (years), mean (SD) | 71.05 (7.77) | 71.20 (7.26) | 70.87 (7.65) | 0.586 | 71.89 (8.21) | 71.01 (7.87) | 0.104 |
| Race/ethnicity (%) | |||||||
| Non-Hispanic white | 59.6 | 46.8 | 63.3 | <0.001 | 47.8 | 61.3 | <0.001 |
| Non-Hispanic black | 14.8 | 14.2 | 14.2 | 17.0 | 14.8 | ||
| Hispanics | 23.4 | 37.4 | 20.2 | 32.6 | 21.7 | ||
| Others | 2.2 | 1.6 | 2.2 | 2.6 | 2.1 | ||
| Educational attainment (%) | |||||||
| Less than high school | 40.1 | 60.0 | 36.7 | <0.001 | 48.0 | 37.8 | <0.01 |
| High school graduate | 24.0 | 13.7 | 22.7 | 23.4 | 27.6 | ||
| More than high school | 35.9 | 26.3 | 40.6 | 28.6 | 34.6 | ||
| Annual household income (%) | |||||||
| <$20,000 | 43.7 | 65.1 | 35.7 | <0.001 | 59.9 | 44.0 | <0.001 |
| $20,000-$75,000 | 43.8 | 29.1 | 49.2 | 35.2 | 43.0 | ||
| >$75,000 | 12.5 | 5.8 | 15.2 | 4.9 | 13.0 | ||
| Smoking status (%) | |||||||
| Nonsmoker | 46.3 | 31.6 | 31.3 | <0.01 | 57.8 | 62.2 | 0.296 |
| Former smoker | 41.7 | 47.4 | 55.7 | 30.4 | 28.6 | ||
| Current smoker | 12.0 | 21.1 | 13.0 | 11.9 | 9.2 | ||
| Alcohol intake >12 drinks/year (%) | 60.9 | 77.1 | 77.1 | 0.996 | 44.1 | 47.4 | 0.336 |
| Moderate/vigorous physical activities (%) | 47.0 | 39.0 | 55.0 | <0.001 | 32.7 | 43.8 | <0.001 |
| Obesity (%) | 31.4 | 26.5 | 27.6 | 0.767 | 36.0 | 35.3 | 0.829 |
| Hypertension (%) | 51.7 | 48.4 | 46.9 | 0.702 | 60.0 | 55.3 | 0.168 |
| Diabetes mellitus (%) | 19.6 | 23.6 | 20.3 | <0.05 | 23.7 | 17.1 | <0.01 |
| Chronic inflammatory markers | |||||||
| CRP (mg/dL) b, medium (IQR) | 0.29 (0.45) | 0.30 (0.45) | 0.23 (0.39) | <0.05 | 0.41 (0.57) | 0.32 (0.50) | <0.05 |
| <3.0 (normal/low risk) | 91.7 | 89.5 | 93.7 | <0.05 | 89.6 | 90.3 | 0.739 |
| ≥3.0 (high risk) | 8.3 | 10.5 | 6.3 | 10.4 | 9.7 | ||
| Plasma fibrinogen | 393.39 | 401.69 | 381.58 | <0.01 | 411.72 | 397.25 | <0.05 |
| (mg/dL), mean (SD) | (83.60) | (92.84) | (84.66) | (85.31) | (79.24) | ||
| Serum albumin (μg/mL) b, medium (IQR) | 4.60 (6.9) | 4.60 (10.55) | 4.70 (7.65) | 0.845 | 4.6 (6.95) | 4.50 (5.20) | 0.264 |
| ≥4.0 (normal) | 86.0 | 93.5 | 89.4 | 0.089 | 84.3 | 81.5 | 0.308 |
| <4.0 (high risk) | 14.0 | 6.5 | 10.6 | 15.7 | 18.5 | ||
| Cognitive functioning (DSST), mean (SD) | 41.69 (18.59) | 34.07 (16.99) | 41.28 (17.81) | <0.001 | 35.79 (17.45) | 45.17 (19.13) | <0.001 |
Note:
a
Descriptive statistics are weighted to adjust for complex survey design.
b
Non-normal distribution continuous variable, median (interquartile range).
Abbreviations: SD, standard deviation; IQR, interquartile range; CRP, C-reactive protein; DSST, digit symbol substitution test.